Grinding mill



R. J- BODINE GRINDING MILL Jan. 6, 1970 3 Sheets-Sheet 1 Filed April 10, 1967 IFIG.I.

INVENTOR.

REID J. oo I NE (A MU H l S ATTORNEY Jan. 6, 1970 R. J. BODINE 3,488,003

GRINDING MILL Filed April 10, 19s? s Sheets-Sheet a INVENTOR.

REID J. B D NE IF IG. 6 BY ,4

HIS ATTORNEY Jan. 6, 1.970 VJ. 50mm; 3,488,008

. GRINDING MILL Filed April 10. 196'? v' 3 Sheds-Sheet 3 INVENTOR. REID J. E DINEI.

CL/w/ H I E ATTORNEY United States Patent 3,488,008 GRINDING MILL Reid J. Bodine, 801 E. Main St., Midway, Utah 84049 Filed Apr. 10, 1967, Ser. No. 629,733 Int. Cl. B02b 5/02, 7/02; B02c 7/08 US. Cl. 241-49 13 Claims ABSTRACT OF THE DISCLOSURE A grinding mill having a feeding chamber for directing grain onto a rotating grinding stone where the grain is urged into a grinding chamber to be ground into flour. The flour is passed from the grinding chamber into a circular turbine housing surrounding the grinding chamber where an air stream, created by turbine blades positioned about the periphery of the grinding stone, picks up the flour and forces it against the turbine housing Where it is deflected with a baffle into a discharge conduit. A particle separator can be provided in communication with, and at an elevation above, the discharge conduit and a spiral channel can be provided in the feeding chamber for controlling the flow of grain into the grinding chamber.

This invention relates to a grinding mill, and in particular, to an air swept grinding mill for grinding cereal grains.

It has become common practice to grind cereal grains such as wheat, and the like, in small grinding mills. One mill that has become very popular is described in United States Patent No. 2,727,695. Grain to be milled is placed into a hopper on top of the machine and from there falls into a spiral chamber which terminates on the face of a rotating grinding stone. The grain escapes from the spiral chamber into a grinding chamber where it is ground into flour. A fan is provided beneath the grinding chamber which creates a downwardly flowing air stream and as the grain is ground it is discharged into the air stream and flows downwardly into the fan housing and is then discharged into a separator. While the mill described in said patent, and other similar mills, are essentially sound in design and operation, several problems and disadvantages have become apparent in their operation and construction. For example, because the fan is secured to the motors drive shaft, between the motor and the rotating grinding stone, the drive shaft must be extended to accommodate this structure thereby increasing the cost of the mill. In addition, the flour produced by the mill must travel along a circuitous path before being discharged into the separator. This, of course, decreases the air flow along the path thereby severely restricting the capacity of the machine to blow ground particles to an elevation above the grinder for separation and also enabling the machine to become plugged more easily. Finally, the grinding mill described in said patent, and other similar mills, are not easily adjustable to vary the coarseness of the flour produced by the mill.

It is accordingly the principal object of this invention to provide an improved grinding mill of relatively small size which overcomes the defects and disadvantages heretofore found in such mills.

It is another object of this invention to provide a grinding mill which is simple in design, inexpensive to construct, and easy to operate.

Still another object of this invention is to provide a grinding mill which provides an efiicient air sweep for blowing flour produced by the mill through a separator which is at an elevation substantially above the elevation of the grinding mills discharge.

Still another object of this invention is to provide a grinding mill which can be easily adjusted to produce flour having a predetermined particle size.

Still another object of this invention is to provide a separator, for separating cracked wheat from flour, in combination with a grinding mill.

Still further objects of this invention will become apparent to those skilled in the art as the invention is better understood by reference to the detailed description appearing hereinafter.

Briefly, the invention comprises a grinding mill having a feeding chamber adapted to direct grain onto a rotating grinding stone where the grain is urged into a grinding chamber to be ground into flour. The flour thus formed is then passed into an air stream created by turbine blades secured to the periphery of the rotating grinding stone. The turbine blades draw air from the exterior of the machine, through ports in the sidewall of the turbine housing, and creates a circular air stream within the housing which picks up the ground flour and forces it against the housing where it is deflected with a directing bafile into a conduit positioned on the circumference of the housing and from thence is blown through a particle separator into a conventional storage bag. Preferably, the feeding chamber is a spiral one formed by a spiral rib fixed to a circular plate. The rib extends downwardly from its associated plate so that the bottom face of the chamber is open. The rib forming the spiral channel has an opening through which the grain may escape into the grinding chamber where it is ground into flour.

So that the invention may be more readily understood and carried into effect, reference is made to the accompanying drawings which are offered by way of example only and are not to be taken as limiting the invention, the scope of which is defined by the appended claims, which obviously embrace equivalent structures and processes.

In the drawings:

FIG. 1 is a front elevation view of the grinding rnill of this invention in communication with a grain separator, in a storage bag, elevated above the grinding mill. A portion of the storage bag is broken away for purpose of clarity.

FIG. 2 is a vertical sectional view of the grinding mill mounted on a vertically positioned electric motor.

FIG. 3 is a top view of the housing used to mount the mill to a motor particularly showing the preferred shape of the directing bafiie.

FIG. 4 is a top view of the grinding stone with turbine blades attached to its periphery.

FIG. 5 is a sectional view of FIG. 4 taken along the plane of line 5-5.

FIG. 6 is a top sectional view of the grinding mill shown in FIG. 1 taken along a plane which passes through the mill along the top face of the rotating grinding stone.

FIG. 7 is an enlarged partial sectional view of the rotating grinding stone and the fixed abrasive stone.

FIG. 8 is a bottom view of a preferred spiral feeding chamber.

FIG. 9 is a plan elevation view of the turbine housing with adjusting slots and with attached grain hopper.

FIG. 10 is a plan elevation view of a grain separator 3 of the type which can be used with the grinding mill of this invention.

Referring now more particularly to the drawings, in FIG. 1 grinding mill is shown supported on base 12 in a substantially vertical position so that hopper 14, for receiving grain to be ground, is at the top end of the mill. Flour produced by the mill is discharged through conduit 16 connected to grain separator 18 which permits the accumulation of fine flour in bag 20 and larger grain particles in vessel 22.

Grinding mill 10 is powered with motor 24 which powers a drive shaft 26. Motor 24 is positioned so that said drive shaft is maintained in a substantially vertical direction. Mill support housing 28, used to support turbine housing 34, hopper 14, and base 36, is bolted to motor 24 with bolts which pass through drill holes 32 in said housing and into taps in the motor. Base 36 is fixedly bolted to mill support housing 28 in a conventional fashion and turbine housing 34 is adjustably secured to said mill support in a fashion hereinafter described. Mill support 28 also supports directing baffie 38, also hereinafter described, for controlling the direction of air flow and particle movement in the turbine housing.

Wheel 40, keyed to shaft 26 in a conventional fashion,

is adapted to freely rotate within a circular shaped cavity in housing 28 while the grinding mill is in operation. Turbine blades 42 are secured to said wheel proximate its circumferential edge to extend radially outward therefrom and also upward away from the top face 44 of wheel 40. Abrasive stone 46 of circular configuration, having a central opening, through which the hub of wheel passes, is cemented in position on wheel 40 so that turbine blades 42 are positioned about the periphery of said abrasive stone 46. Preferably, turbine blade 42 also extends upwardly beyond the top face of abrasive stone 46. As motor 24 is energized, shaft 26 with attached wheel 40, is rotated thereby rotating turbine blades 42 and abrasive stone 46 wherein stone 46 functions as the grinding medium for grain passed thereon.

. Supporting plate 48 is bolted to turbine housing 34 and depending from said plate 48 is an annular abrasive stone 50 which is rigidly secured to the plate by a cement or other suitable medium. Also depending from supporting plate 48 is feed control plate 52 which is rigidly secured to said supporting plate by a plurality of bolts 54 which pass through drill holes 56 provided in the top face of said feed plate and into threaded engagement with tapped holes in said support plate 48.

Hopper 14 is supported on top of turbine housing 34 in a conventional fashion. It is also within the scope of this invention to provide housing 34 and hopper 14 as a unitary structure. Said hopper is tapered to funnel grain onto the top face of plate 48 which slopes towards a central circular opening 58 in feed plate 52. The grain is fed through the circular opening and onto rotating abrasive stone 46. The feed control plate 52, in cooperation with rotating abrasive stone 46, serves to control the rate of flow of grain into an annular grinding chamber 60, of triangular cross-section, as shown in FIGS. 2 and 7. The grinding chamber is formed by the stationary peripheral surface 62 of the feed control plate 52, and a chamfered inner edge 63 of the annular abrasive stone 50, with top surface '61 of the rotating abrasive stone 46 serving as a base for the grinding chamber.

As shown in FIGS. 2, 6, and 8, feed control plate 52 includes a downwardly extending circumferential rib 64 of varying thickness and of a depth corresponding to the approximate breadth of abrasive stone 50 so that their bottom surfaces are in the same horizontal plane. The rib 64 extends about a substantial portion of the circumference of the feed control plate except for a break by a relatively small opening 70. In addition, feed control plate 52 can be provided with a spiral rib 66 of the same depth as circumferential rib 64 but which follows the path of a spiral to form a spirally progressing chamber of rectangular cross-section. The spiral rib 66 starts at a point tangent to the circular opening 58 of the feed control plate 52 and progresses spirally toward the thickest part of circumferential rib 64. To permit the passage of grain through feed control plate 52, spiral rib 66 has openings formed therein.

The bottom edges of circumferential ribs 64, spiral ribs 66, and abrasive stone 50 are all in the same plane, in juxtaposition with the top surface of the rotating stone 46 which functions as a base to enclose the spiral channel as well as the grinding chamber 60. The spiral rib 66 in conjunction with the opening in said rib bperates in the manner of a valve to control the flow of grain into grinding chamber 60. When small mills are used, spiral ribs 66 are not attached to the feed control plate 52. Instead, circumferential rib 64 is provided with an inwardly extending enlarged end 68 which imparts a spiral effect to the inside surface of said rib 64 along a portion of its length. As previously indicated, opening 70 is provided between said enlarged first end of rib '64 and the opposite end of the rib which allows grain to flow therethrough into grinding chamber 60.

The abrasive stone 46 rotates in a direction opposite to the progression of the spiral of ribs 66 and/or 64 so that as it rotates it tends to urge the grain to the beginning of the spiral at the center portion of the feed plate 52 and away from grinding chamber 60. Although the rotation of the abrasive stone, in operation with the feed control plate, tends to urge the grain away from grinding chamber 60, the grain resting on stone 46 is also subjected to centrifugal force by reason of the rotation of stone 46. Such centrifugal force tends to urge the grain outwardly away from the center of the stone and towards grinding chamber 60 thereby causing the grain to escape through opening 70 into the grinding chamber, where it is triturated into flour. Thus, the centrifugal force created by the rotating stone 46 serves to feed the grain into the grinding chamber while the tendency of the grain to follow the spiral chamber of the feed control plate opposes the effect of the centrifugal force to limit the flow of grain into grinding chamber 60.

Trituration of the grain in the grinding chamber is accompanied by reason of the abrasive action on the grain by stones 46 and 50 when stone 46 is rotated relative to stone 50. Once the grain enters grinding chamber 60 the centrifugal force created by rotating stone 46 urges it into the apex of the chamber where it is subjected to the abrasive action of the stones thus described. The grain is thereupon ground to a fineness determined by the size of a gap 72 established by the spacing of stones 46 and 50 with respect to each other.

After the grain has been ground fine enough to pass through gap 72 it is discharged into turbine chamber 74 between turbine blades 42 secured to wheel 40. Turbine chamber 74 is an annular chamber of circular configuration bounded about its periphery with turbine housing 34, on its bottom with mill support housing 28 and its top with support plate 48. When wheel 40, with attached turbine blades, is rotated, an air stream is created which moves about the turbine chamber in a circular fashion in the direction of rotation of said wheel. Particles passing through gap 72 are drawn into the air Stream and circulated through turbine chamber 74 until they are removed therefrom through exhaust port 76 in turbine housing 34 and into exhaust conduit 16 which is secured to and preferably tangential with housing 34. The turbine blades draw air from the exterior of the grinding machine through a port or series of ports 78 positioned in turbine housing 34 as shown in FIGURE 6, and a directing bafile 38, preferably secured to mill support housing 28, is positioned between said intake port 78 and exhaust port 76 so that the air drawn into the turbine chamber through intake port 78 is directed out of turbine chamber 74 through exhaust port 76 after it has picked up finely ground flour discharged into the turbine housing through gap 72.

By using a turbine and turbine chamber of the type herein described very substantial air discharge pressures are obtained. Accordingly, a separator of the type shown in FIGS. 1 and 9, which is elevated at a position substantially above the outlet conduit 16, can be attached to the grinding machine. Grindings produced by the mill are blown through conduit 16 into upwardly extending conduit 80, which is attached to conduit 16 in a conventional fashion with quick connector 82, and into screened separator 84. A portion of the grindings are blown through separator 84 into bag 20 and the remaining portion of the relatively larger particles, termed, cracked wheat, are retained within the separator and move by gravity into conduit 88 which leads to st rage vessel 22. Bag 20 is supported in an upright position with support rod 90 which is fixedly connected at one end to conduit 16 in a conventional fashion.

The proportion of cracked wheat and flour produced by the grinding mill of this invention can be readily varied by adjusting the size of gap 72 between rotating grinding stone 46 and stone 50. The size of gap 72 is controlled by adjusting the height of supporting plate 48 with respect to abrasive stone 46. Supporting plate 48 can be adjusted in two different fashions. Firstly, the plate is secured to turbine housing 34 with bolts 92 which pass through vertically extending elongated slots 94 in said turbine housing 34. By merely loosening said bolts 92 support plate 48 can be raised or lowered to a predetermined position. In operation, this adjustment is generally made only for the purpose of compensating for the wear of stones 46 and 50. Since support plate 48 is fixedly attached to turbine housing 34, the size of gap 72 can also be varied by changing the elevation of said turbine housing 34 with respect to mill housing 28. As shown in FIGS. 2, 3 and 9, turbine housing 34 is connected to mill housing 28 with bolts 96 (preferably three bolts are used) which pass through slots 98 in said turbine housing 34. As particularly shown in FIG. 9, slots 98 are angled with respect to the vertical axis of the mill and accordingly, when bolts 96 are loosened, turbine housing 34 can be rotated wherein supporting plate 48 attached to turbine housing 34 is raised or lowered, depending on the direction of rotation of housing 34 with respect to mill support housing 28.

To adjust the mill for operation it is preferred to loosen bolts 96 and rotate turbine housing 34 so that said housing is at its lowest possible elevation, i.e., bolts 96 are positioned proximate the top portion of angled slots 98. Supporting plate 48 is then adjusted by loosening bolts 92 so that the stationary abrasive stone 50 is positioned substantially adjacent to rotating stone 46. This, then, will result in grinding conditions in which an extremely fine flour is produced. Bolts 92 are then tightened so that fixed stone 50 is tightly secured to turbine housing 34. This adjustment need not be made again until the grinding stones become worn thereby preventing production of finely ground flour. The proportion of cracked wheat and flour can then be controlled by merely loosening bolts 96 and rotating turbine housing 34. So that this may be more easily accomplished, bolts 96 are preferably provided with enlarged flattened heads that can be easily grasped and turned by an individual with his fingers rather than requiring the use of a wrench.

Whereas there is here illustrated and specifically described a certain preferred apparatus which is presently regarded as the best mode of carrying out my invention, it should be understood that various changes can be made and other construction adopted without departing from the inventive subject matter particularly pointed out and claimed.

I claim:

1. A grinding mill having driving means with an upright extending drive shaft for powering the mill; an abrasive stone mounted on said drive shaft to rotate with said shaft; turbine blades mounted about the periphery of said abrasive stone; a turbine housing connected to said driving means and positioned around said turbine blades to form an air circulation chamber around said abrasive stone; an abrasive annular stone secured to said turbine housing with the lower surface of said annular stone positioned adjacent to the upper face of said abrasive stone with a predetermined gap there between; an exhaust port in said turbine housing opposite from said turbine blades; an air intake port in said housing opposite from said turbine blades and spaced apart from said exhaust port; and a directing bafile connected to said housing betwee'n said intake port and said exhaust port, wherein the rotation of said turbine blades draws air through said intake port into said circulation chamber and exhaust said air from said circulation chamber through said exhaust port.

2. The grinding mill of claim 1 wherein said turbine blades are radially mounted to said abrasive stone.

3. The grinding mill of claim 1 wherein a feed control plate is supported by said turbine housing above said annular stone which has a central opening through which grain is admitted to fall upon said abrasive stone wherein said feed control plate has a circumferential rib secured to its periphery which extends downwardly from said feed control plate so that the bottom edge of said rib is contiguous to the upper face of said abrasive stone, said circumferential rib having an opening through which the grain may escape.

4. The grinding mill of claim 3 wherein the inside surface of said circumferential rib secured to said feed control plate is shaped to spiral in a direction opposite to the direction of rotation of said abrasive stone.

5. The grinding mill of claim 4 wherein a spiral rib is secured to said feed control plate which extends downwardly from said plate so that its bottom edge is in the approximate plane of the bottom edge of said circumferential rib, said spiral rib progressing from the central portion of said feed control plate in a direction opposite the direction of rotation of the abrasive stone and having a plurality of openings for passing grain therethrough.

6. The grinding mill of claim 1 wherein said turbine housing is adjustably secured to said driving means for varying the size of said gap between the abrasive stone and the annular stone.

7. The grinding mill of claim 6 wherein said turbine housing is adjustably secured to a flange mounted on said driving means with screw means wherein said screw means pass through angled slots in said turbine housing and are anchored in said flange.

8. The grinding mill of claim 1 wherein said annular stone is adjustably mounted to said turbine housing.

9. The grinding mill of claim 8 wherein said turbine housing is adjustably secured to said driving means for varying the size of said gap between the abrasive stone and the annular stone.

10. The grinding mill of claim 9 wherein said turbine housing is adjustably secured to a flange mounted on said driving means with screw means wherein said screw means pass through angled slots in said turbine housing and are anchored in said flange.

11. The grinding mill of claim 1 wherein said turbine blades extend upwardly and outwardly beyond said abrasive stone.

12. The grinding mill of claim 11 wherein said exhaust port is provided in communication with an exhaust conduit positioned tangential to the periphery of said circulation chamber.

13. The grinding mill of claim 12 wherein said exhaust conduit is in communication with a grain separator which is positioned at an elevation above said grinding mill.

(References on following page) 7 8 References Cited 2,727,695 12/1955 Harries 24156 2,980,353 4/1961 Brown 241 -259 UNITED STATES PATENTS ROBERT C. RIORDON, Primary Examiner Nielsen 241259 X Martin 2415 5 5 D. G. KELLY, Assistant Examiner Wood 241-259 X Tanner 241--55 X CL Bakewell 241286 X 241--55, 100, 259, 286 

